1. Field
This disclosure relates to methods for comparing music tracks.
2. Description of the Related Art
Current music analysis, personalization, and recommendation systems rely on descriptive metadata describing each song or track. The metadata may be stored in a database and processed to identify, recommend, and/or retrieve similar songs. Present systems may rely on either acoustic metadata or on cultural metadata.
Within this patent, “acoustic metadata” refers to a numerical or mathematical representation of the sound of a track. Acoustic metadata may take the form of one or more vectors, matrices, lists, tables, and other data structures. Acoustic metadata may be derived from analysis of the music signal. One form of acoustic metadata, commonly termed an “acoustic fingerprint”, may uniquely identify a specific track. Other forms of acoustic metadata may be formed by compressing the content of a track while retaining some or all of its musical characteristics. Acoustic metadata may include both temporal information such as tempo, rhythm, beats, tatums, or structure, and spectral information such as melody, pitch, harmony, or timbre.
Techniques for deriving acoustic metadata from music signals are known. Since the music signal may be converted into one or more feature vectors, such techniques may be known as “music vectorization”. For example, copending patent application Ser. No. 12/061,374, entitled “Method and Apparatus for Automatically Segueing Between Audio Tracks”, filed Apr. 2, 2008, describes a method for deriving acoustic metadata wherein a track may be divided into segments and the spectral content of each segment may be compressed into a timbral vector. An acoustic fingerprint, termed a “timbral signature” may then be calculated as the covariance matrix of the timbral vectors. Paragraphs 0030-0035 and 0048-0051 as filed and the associated figures of application Ser. No. 12/061,374 are incorporated herein by reference. Other methods for deriving acoustic metadata are described in U.S. Pat. No. 5,918,223, U.S. Pat. No. 7,013,301, and U.S. Pat. No. 7,277,766.
Within this patent, “cultural metadata” refers to text-based information describing listeners' reactions to a track or song. Cultural metadata may be derived from expert opinion such as music reviews or classification of music into genres. Cultural metadata may be derived from listeners through Web sites, surveys, and the like. Cultural metadata may include sales data, shared collections, lists of favorite songs, and any text information that may be used to describe, rank, or interpret music. Cultural metadata may also be generated by a community of listeners and automatically retrieved from Internet sites, chat rooms, and the like. Published U.S. patent application US 2007/0240557 A1, the entire content of which is incorporated herein by reference, describes (paragraphs 0034-0041 and the associated figures) a method for extracting cultural metadata from text pages obtained by searching the Internet. U.S. Pat. No. 6,539,395 describes another method for accumulating cultural metadata. Cultural metadata may be obtained through metadata services such as All Media Group (AMG, a unit of Macrovision), Gracenote, and others.
Cultural metadata may take the form of one or more vectors, matrices, lists, tables, and other data structures. A form of cultural metadata particularly useful for comparing music is a description vector. A description vector is a multi-dimensional vector associated with a track, album, or artist. Each term of the description vector indicates the probability that a corresponding word or phrase would be used to describe the associated track, album or artist. Copending patent application Ser. No. 12/100,966, entitled “Automatically Acquiring Acoustic and Cultural Information About Music”, filed Apr. 20, 2008, the entire content of which is incorporated herein by reference, describes a method for developing description vectors associated with music tracks.
Within this patent, “explicit metadata” refers to factual or explicit information relating to music. Explicit metadata may include album and song titles, artist and composer names, other credits, album cover art, publisher name and product number, and other information. Explicit metadata is generally not derived from the music itself or from the reactions or opinions of listeners. AMG and Gracenote provide explicit metadata (names, credits, product numbers, etc.) and cultural metadata (styles, genres, moods, themes, similar artists and/or songs, rankings, etc.) for a large library of songs or tracks. The metadata available from AMG's Allmusic.com Web site is believed to be generated primarily by a network of hundreds of professional music critics and reviewers.
MusicIP Corporation provides an acoustic fingerprinting service commonly referred to as Music DNS (Digital Naming System). Music DNS calculates acoustic metadata from the content of a track. Music DNS may be used to uniquely identify specific tracks.
Throughout this description, elements appearing in block diagram are assigned three-digit reference designators, where the most significant digit is the figure number and the two least significant digits are specific to the element. An element that is not described in conjunction with a block diagram chart may be presumed to have the same characteristics and function as a previously-described element having a reference designator with the same least significant digits.
Throughout this description, elements appearing in flow charts are assigned three-digit reference designators, where the most significant digit is the figure number and the two least significant digits are specific to the element. An element that is not described in conjunction with a flow chart may be presumed to have the same characteristics and function as a previously-described element having a reference designator with the same least significant digits.